Wiping contact rotary switch



Jan. 28, 1964 H. F. MASON 3,119,906

WIPING CONTACT ROTARY SWITCH Filed March 19, 1962 v 2 Sheets-Sheet 1 x6/ 502 FIG. 2.

40 2ft: 38 Q I IL Z2 22 it: 30 3 342 30 is; i; 64 2 mmlim.

INVENTOR HOWARD FT MASON 8) ATTORNEYS HARE/5, K/EcH, RUSSELL. & KERNJan. 28, 1964 H. F. MASON 3,119,906

WIPING CONTACT ROTARY SWITCH Filed March 19, 1962 2 Sheets-Sheet 2INVENTOR HOWARD E MASON BY HIS ATTORNEYS HARE/S, K/ECH, Russfiu. 6: KERNUnited States Patent 3,119,9ll6 WHING (IQNTACZT RUEARY SWHCH Howard F.Mason, Los Angeles, Calif assignor to Mason Electric Corporation, LosAngelles, Qalitl, a corporation of California Filed Mar. 19, 1962, Ser.No. 180,639 14 Qlairus. (Cl. Nil-11) The present invention relates ingeneral to switches and, more particularly, to rotary switches, generalobjects of the invention being to provide a completely reliable rotaryswitch which will maintain uniform contact resistances throughout longperiods of use, which is positively detentcd in its operating positions,which may be composed of more than one section each separately detentedinstead of utilizing a master detent for all sections, which iscompletely versatile in that it can be made up in various configurationsfor dirl'erent usages with the same parts, and the like.

An important object of the invention is to provide a rotary switch whichincludes, or each section of which includes: an annular stator providingan annular, concave contact path; the contact path including an annularcontact row of circumferentially spaced, stationary contacts; thecontact path including an annular insulating row or circumferentiallyspaced, insulating segments which is parallel to the contact row; theinsulating segments being axially aligned, respectively, with thecircumferential spaces between the stationary contacts; a rotor withinthe stator and rotatable about the axis thereof; a movable contactcarried by and movable radially relative to the rotor and engaging thecontact path; spring means biasing the movable contact radiallyoutwardly into engagement with the contact path; the stator providing anannular detent path paralleling the contact and insulating rows of thecontact path; the detent path having circumierentially spaced points ofmaximum radius axially aligned, respectively, with the stationarycontacts; the detent path having c-ircumferentially spaced points ofminimum radius axially aligned, respectively, with the insulatingsegments; a detent carried by and movable radially relative to the rotorand engaging the detent path; and spring means biasing the detentradially outwardly into engagement with the detent path.

It will be noted that, with the foregoing construction, detenting isaccomplished in a positive manner within the switch itself, or withineach section of the switch itself. Another important advantage of theforegoing construction is that the movable contact cannot track metalfrom the stationary contact onto the insulaing segments because of thefact that the row of insulating segments is axially offset from andparallel to the row of stationary contacts. Thus, different portions ofthe movable contact engage the stationary contacts and the insulatingsegments to avoid metal tracking.

Another object of the invention is to provide a rotary switch of theforegoing nature wherein there are two rows of stationary contacts andtwo corresponding rows of insulating segments all axially spaced apart,the axial dimension of the movable contact being sufficient to bridgethe contact and insulating rows. A related object is to provide a statorwherein the insulating rows are between the contact rows and wherein thedetent path is between the insulating rows.

Still another object of the invention is to provide a rotary switchwherein the movable contact is a Wiping contact slidably engaging thecontact path.

A further object of the invention is to provide a stator Patented is.as, trees which is divided into two halves in a transverse planecoinciding with the midplane of the detent path, which simplifiesmanufacture.

Yet another object is to provide a rotary switch wherein the radius ofthe insulating segments is slightly less than the radius of thestationary contacts so that the insulating segments displace the wipingcontact radially inwardly out of engagement with the stationary contactsas the rotor rotates. Thus, in effect, the insulating segments lift thewiping contact from the stationary contacts, thereby producing a fasterbreak.

An additional object of the invention is to provide a constructionwherein the spring means for biasing the wiping contact radiallyoutwardly into engagement with the contact path includes two compressionsprings substantially radially aligned with the respective rows ofstationary contacts. With this construction, the wiping contact ispressed against each pair of stationary contacts by correspondingsprings. A related object is to provide springs having substantiallyconstant spring rates so that wear does not significantly affect contactpressure.

Another object of the invention is to provide a construction wherein thewiping contact is radially sl-idable in a longitudinally oriented,radially extending groove in the rotor.

A further object of the invention is to provide a construction whereineach wiping contact includes two circuin'ferentially abutting, wipingcontact elements carried in the corresponding groove in the rotor, thewiping contact elements having convex wiping shoes slidably engaging thecontact path and respectively extending circumferentially in oppositedirections. With this construction, a make before break or transfer typeof switching is achieved. Alternatively, where each wiping contactincludes but a single contact element, a break before make type ofswitching is achieved.

Another object in connection with the double-contactelement structurediscussed above is to provide independent springs for the two contactelements, whereby each contact element is biased into engagement withthe contact path independently. A further object in this connection isto provide two compression springs in engagement with one contactelement of each pair in radial alignment with the stationary contactrows, and to provide a single compression spring in engagement with themidpoint of the other contact element of such pair.

Yet another object is to provide a rotary switch wherein the diameter ofthe rotor approaches the inside diameter of the stator to provide asmall, arc quenching annular clearance therebetween.

The foregoing objects, advantages, features and results of the presentinvention, together with various other objects, advantages, features andresults thereof which will be quite evident to those skilled in theswitch art in the light of this disclosure, may be achieved with theexemplary embodiments of the invention described in detail hereinafterand illustrated in the accompanying drawings, wherein:

FIG. 1 is a side elevational view on a reduced scale illustrating awiping contact rotary switch which embodies the invention;

FIG. 2 is a longitudinal sectional view of the rotary switch of FIG. 1on an enlarged scale;

FIG. 3 is a fragmentary perspective view of an annular stator of therotary switch of the invention;

FIG. 4 is a perspective view of a rotor of the rotary switch of theinvention;

FIG. 5 is a fragmentary sectional view taken approximately along theirregular arrowed line 5 of FIG. 2;

FIG. 6 is a view similar to FIG. 5, but showing various parts indifierent operating positions;

FIGS. 7 and 8 are views respectively similar to FIGS. 5 and 6, butshowing another embodiment of the invention;

FIG. 9 is a fragmentary sectional view taken approxi mately along thearrowed line 9-9 of FIG. 7; and

FIG. 10 is a perspective view of a double-contact-element wiping contactincorporated in the embodiment of FIGS. 7 to 9 of the drawings.

The rotary switch or" the invention is designated generally by thenumeral 29 and includes a generally cylindrical housing 22 having anactuating shaft 24 projecting axially therefrom. The housing 22 includesan annular stator 26 within which a rotor 28 is rotatable, the rotorbeing mounted on and keyed to the shaft 24, as by being telescoped ontoa squared portion of the shaft.

The housing 22 includes two axially spaced end walls 3% and 32respectively providing bearings 34 and 36 for the shaft 24 and receivingthe annular stator 26 there between, the stator being separated from theend walls 30 and 32 by annular insulating spacers 38 and an,respectively. The various components of the housing 22 are clampedtogether by screws 42 extending therethrough. The bearing 36 has theform of a bushing which is externally threaded to permit panel mountingof the switch in a conventional manner, and the projecting end of theshaft 24 is designed to accept a knob, not shown, for manual actuation.However, other mounting and actuating arrangements may be used.

The internal surface of the annular stator 26 provides an annular,concave contact path 44 for one or more wiping contacts carried by therotor 23, only one wiping contact being shown for convenience and beingdesignated by the numeral 46. The contact path includes two axiallyspaced, parallel, annular contact rows of circumferentially spaced,stationary contacts 48 respectively embedded in annular stator halves 50having adjacent ends in abutting relation in the midplane of the stator.The stationary contacts 48 of each contact row may be molded directlyinto the corresponding stator half 56 and project radially outwardlythrough such stator half to permit external wiring connections thereto.The stationary contacts 48 of each contact row may be separate, orinterconnected in various ways, depending upon the use to be made of theswitch 20.

The axial dimension of the wiping contact 46 is sufficient for it tobridge the two rows of stationary contacts 48, each stationary contactbeing axially aligned with a corresponding stationary contact in theother row. With this bridging type of action, the stationary contacts 48of one row may all be interconnected, as shown in FIG. 3, andthestationary contacts of the other row may all he separate to controlseparate circuits. However, various of the stationary contacts of theother row may also be interconnected in some instances.

Axially intermediate the rows of stationary contacts 48 are two axiallyspaced, parallel, annular rows of circumferentially spaced, insulatingsegments 52. The insulating segments of each insulating row are axiallyaligned, respectively, with the circumferential spaces between thestationary contacts 48 of each contact row. Thus, the wiping contact as,in moving circumferentially from one pair of stationary contacts 48 tothe next, slides over the intervening pair of insulating segments 52.Since the rows of insulating segments 52 are axially intermediate andaxially spaced from the rows of stationary contacts t8, the portions ofthe wiping contact 46 which engage the insulating segments 52 are spacedaxially "from the portions of the wiping contact which engage thestationary contacts This misalignment thus prevents metal tracking fromthe stationary contacts 53 across the insulating segments 52, which isan important feature.

As best shown in FIGS. 5 and 6 of the drawings, the radius of theinsulating segments 52 is slightly less than the radius of thestationary contacts 48 so that the insulating segments displace thewiping contact 46 radially inwardly out of engagement with thestationary contacts as the rotor 28 rotates. Thus, the pair ofinsulating segments 52 intervening two adjacent pairs of stationarycontacts 48 in effect lifts the wiping contact 46 out of engagement withthe first pair of stationary contacts so as to rapidly increase the gapbetween the wiping contact and the pair of stationary contacts which thewiping contact is disengaging. Arcing is therefore minimized, which isan important feature. It might also be pointed out in this connectionthat the radial clearance between the rotor 2d and the contact path 5 issmall so that it has an arc quenching effect as the wiping contact 4-6is displaced circumferentially away from each pair of stationarycontacts 43.

The annular stator 26 provides an annular detent path 5d located betweenthe rows of insulating segments 52 and bisected by the transversedividing plane provided by the two halves 5d of the stator. The detentpath 54 includes circumferentially spaced points or peaks 56 of minimumradius axially aligned, respectively, with the insulating segments 52 ofeach row, and circumferentially spaced points or valleys 53 of maximumradius axially aligned, respectively, with the stationary contacts 48 ofeach contact row. The rotor 28 carries one or more radially movabiedetents, one being shown and being identified by the numeral ea,slidable circumferentially along the detent path 54- over the peaks 56and across the valleys 58 thereof. As will be apparent, when the detent6t) is in one of the valleys 53, it releasably locks the rotor 28 in oneof its operating positions, wherein the wiping contact as bridges thestationary contacts 48 of one pair thereof. This condition is shown inFIG. 5 of the drawings. FIG. 6 of the drawings shows the detent 60riding over one or" the peaks 56 as the wiping contact 46 traverses anadjacent pair of insulating segments 52.

The rotor 23 is provided with a plurality of circumferentially spaced,longitudinally oriented, radially extending grooves 62 which are spacedapart circumferentially a distance equal to the circumferential spacingof the pair of stationary contacts and the pairs of insulating segments52.

The rotor 28 is provided with three axially spaced, radially extendingholes in register with each groove s2 and wider than such groove sothat, in eliect, each such hole forms opposed, radially extendinggrooves in the respective side walls of each groove 62. The middle holewhich coincides with each groove 62 is designated by the numeral 6d, theother two be'ng identified by the numeral 66. The holes 64 communicateat their inner ends with smaller, coaxial, radial holes 63 in the rotor23.

The purpose of the foregoing construction of the coinciding grooves 62and holes as and as is to provide a construction wherein each groove mayreceive either a wiping contact in, or a detent as, withoutmodification. Also, as will become apparent in connection with asubsequent description of the embodiment of FIGS. 7 to 10 of thedrawings, each groove 62 is capable of accepting adouble-contact-element wiping contact 79 without modification. Thus, thesame grooves 62 are capable of receiving various elements, which is animportant feature of the invention.

The wiping contact 46 is generally U-shaped in side elevation, as bestshown in FIG. 2 of the drawings, and includes two arms respectivelyradially slidable in the portions of one of the grooves 62 which areaxially outwardly of the outer holes as. The wiping contact a6 is biasedradially outwardly into positive engagement with the contact path 44- bytwo compression coil springs '72 respectively disposed in and secured tothe rotor by the corresponding axially outer holes 66. The springs 72are seated at their inner ends on the radially inner wall of thecorresponding groove 62, and are seated at their outer ends against thecrossbar of the Ushaped wiping contact 46. With this construction, avery simple means of assembling the wiping contact 46 and the springs'72 with the rotor 28 is provided, which is an important feature of theinvention.

It will be noted that the axially outer holes 66 are sub-- stantially inradial alignment with the rows of stationary contacts 48. Consequently,the springs 72 respectively bias the wiping contact 46 directly intoengagement with the stationary contacts 48 of each pair. As hereinbeforeindicated, the spring rates of the springs 72 are substantially constantso that the spring force with which the wiping contact is radiallybiased remains substantially constant even after appreciable Wear.

The detent 60 has the form of a pin which is radially slidable in themiddle hole 64 of the particular groove 62 in which it is disposed. Thedetent 60 is provided at its inner end with a reduced-diameter stem 74which extends radially inwardly into the corresponding hole 68 in therotor 28. A compression coil spring '76 is disposed within thecorresponding middle hole 64 and encircles the stem '74- of the detent69, being seated at its inner end against the inner end of thecorresponding hole 64, and being seated at its outer end against anannular shoulder formed t the outer end of the stem 74. Again, thisprovides a very simple means of assembling the detent 60 and its spring'76 with the rotor 28.

Also, as hereinbefore pointed out, the same groove 62, with theforegoing construction, can accept either a wiping contact 46, or adetent 60, without modification. Thus, the same parts can be used invarious arrangements, which is an important feature.

As will be apparent from FIGS. 5 and 6 of the drawings, the wipingcontact 46 operates with a break before make type of action. The presentinvention is equally adaptable to a make before break or transfer typeof action by utilizing a different construction for the wiping contact,wherein the circumferential extent of the wiping contact is larger. Thepreferred construction for this purpose, which includes thehereinbefore-referred-to double-contact-element wiping contact '79, isshown in FIGS. 7 to of the drawings.

Referring thereto, the wiping contact 70 includes two Wiping contactelements 82 and 84 both disposed in one of the grooves 62 in the rotor28 in circumferentially abutting relation. The contact elements d2 and84 are respectively provided with convex wiping shoes 86 and 38 whichare slidably engageable with the contact path :4 and which extendcircumferentially in opposite directions. The Wiping shoes 86 and 38have suilicient circumferential width to bridge two adjacent pairs ofthe stationary contacts 4% simultaneously, as shown in FIG. 8 of thedrawings, to provide the desired make before break or transfer type ofaction.

The contact elements 32 and 34- are of similar construction, butoppositely oriented, and both are generally U-shaped in side elevation,being similar to the wiping contact 46 in this respect. The contactelement $2 is biased radially outwardly by two compression coil springs9t; disposed in the outer holes 66 coinciding with the correspondinggroove 62. The springs 90 are seated at their inner ends against theinner ends of the holes 66, and are seated at their outer ends againstthe crossbar of the contact element $2. Thus, the contact element 82 isspring biased in the same manner as the wiping contact 46.

Engagement of the springs 90 with the contact element 34 is prevented byradially outwardly-relieving the crossbar of the contact element 84, asindicated at 92. Intermediate the reliefs 92, the contact element 84 isprovided with a radially-inwardly-extending tab 94 which extendsradially inwardly beyond the crossbar of the contact element 82. Acompression coil spring 96 disposed in the corresponding central hole 64is seated against the tab 94 and against the inner end of such centralhole. Consequently, the spring 96 acts only on the contact element 84,applying substantially equal contact pressures on both stationarycontacts d8 of the particular pair which engages. To provide the samecontact pressure for the contact element 84- as for the contact element82, the spring 96 may be heavier than the springs 9%.

Although exemplary embodiments of the invention have been disclosedherein for purposes of illustration, it will be understood that variouschanges, modifications, and substitutions may be incorporated in suchembodiments without departing from the spirit of the invention asdefined by the claims which follow:

I claim:

1. In a switch, the combination of:

(a) a stationary member providing a contact path;

([7) said contact path including a contact row of spaced,

stationary contacts;

(0) said contact path including an insulating row of spaced, insulatingsegments which is parallel to and spaced from said contact row;

(d) said insulating segments being laterally aligned, respectively, withthe spaces between said stationary contacts;

(6) a movable member movable along said contact path;

( a movable contact carried by said movable member and movable towardand away from and engageable with said contact path;

g) spring means biasing said movable contact into engagement with saidcontact path;

(11) said stationary member providing a detent path paralleling saidcontact and insulating rows of said contact path;

(i) said detent path having spaced valleys laterally aligned,respectively, with said stationary contacts;

(j) said detent path having spaced peaks laterally aligned,respectively, with said insulating segments;

(k) a detent carried by said movable member and movable toward and awayfrom and engageable with said detent path; and

(1) spring means biasing said detent into engagement with said detentpath.

2. In a rotary switch, the combination of:

(a) an annular stator providing an annular, concave contact path;

(b) said contact path including an annular contact row ofcircumferentially spaced, stationary contacts;

(0) said contact path including an annular insulating row ofcircumfere-ntially spaced, insulating segments which is parallel to andspaced axially from said contact row;

(d) said insulating segments being axially aligned, re-

spectively, with the circumferential spaces between said stationarycontacts;

(e) a rotor within said stator and rotatable about the axis thereof;

(1) a movable contact carried by and movable radially relative to saidrotor and engaging said contact path;

(g) spring means biasing said movable contact radially outwardly intoengagement with said contact path;

(It) said stator providing an annular detent path paralleling saidcontact and insulating rows of said contact path;

(1) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts;

(j) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments;

(k) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(1) spring means biasing said detent radially outwardly into engagementwith said detent path.

3. In a rotary switch, the combination of:

(a) an annular stator providing an annular, concave contact path;

(12) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows eing axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

() said contact path including two axially spaced, parallel, annularinsulating rows or" circnmferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(c) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) a rotor within said stator and rotatable about the axis thereof;

(It) a movable contact carried by and movable radially relative to saidrotor and engaging said contact path;

(1') the axial dimension of said movable contact being suflicienttobridge said contact rows;

(j) spring means biasing said movable contact radially outwardly intoengagement with said contact path;

(k) said stator providing an annular detent path paralleling saidcontact and insulating rows of said contact path;

(I) said detent path having circumferentially spaced points of maximumradius axially aligned, respec tively, with said stationary contacts ofeach of said contact rows;

(in) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach or said insulating rows;

(11) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(0) springs means biasing said detent radially outwardly into engagementwith said detent path.

4. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(12) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(0) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(0!) said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(a) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(1) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) a rotor within said stator and rotatable about the axis thereof;

(h) a wiping contact carried by and movable radially relative to saidrotor and slidably engaging said contact path;

(i) the axial dimension of said wiping contact being suificient tobridge said contact rows;

(j) spring means biasing said wiping contact radially outwardly intoengagement with said contact path;

(It) said stator providing an annular detent path paral- 5. In a wipingcontact rotary switch, the combination (a) an annular stator providingan annular, concave contact path;

(b) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(0) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(e) said insulaing segments of one of said insulating rows being axiallyaligned, respectively, with said insulating segments of the other ofsaid insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

([1) a rotor within said stator and rotatable about the axis thereof;

(i) a wiping contact carried by and movable radially relative to saidrotor and slidably engaging said con tact path;

(j) the axial dimension of said wiping contact being sufficient tobridge said contact rows;

(k) spring means biasing said wiping contact radially outwardly intoengagement with said contact path; (I) said stator providing an annulardetent path between said insulating rows of said contact path;

(in) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

(11) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

(0) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

( 2) spring means biasing said detent radially outwardly into engagementwith said detent path.

6. In a wiping contact rotary switch, the combination I (at) saidcontact path including two axially spaced,

parallel, annular insulating rows of circumferentially spaced,insulating segments spaced axially from said contact rows, respectively;

(e) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(11) a rotor within said stator and rotatable about the axis thereof;

(i) a wiping contact carried by and movable radially relative to saidrotor and slidably engaging said contact path;

(j) the axial dimension of said wiping contact being sutficient tobridge said contact rows;

(k) spring means biasing said Wiping contact radially outwardly intoengagement with said contact path;

(I) said stator providing an annular detent path between said insulatingrows of said contact path;

(In) said stator being divided into two halves in a transverse planecoinciding with the midplane of said detent path;

(It) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

() said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

(p) a detent carried by and movable radially relative to said rotor andengaging said detent path; and (q) spring means biasing said detentradially outwardly into engagement with said detent path.

7. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(1)) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(0) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(2) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(7) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contact of each of said contact rows;

(g) said insulating rows being between said contact rows;

(12) a rotor within said stator and rotatable about the axis thereof;

(i) a Wiping contact carried by and movable radially relative to saidrotor and slidably engaging said contact path;

(j) the axial dimension of said wiping contact being suliicient tobridge said contact rows;

(k) spring means biasing said wiping contact radially outwardly intoengagement with said contact path;

(I) the radius of said insulating segments being slightly less than theradius of said stationary contacts so that said insulating segmentsdisplace said wiping contact radially inwardly out of engagement withsaid stationary contacts as said rotor rotates;

(m) said stator providing an annular detent path be tween saidinsulating rows of said contact path;

(it) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

(0) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

(p) a detent carried by and movable radially relative to said rotor andengaging said detent path; and (q) spring means biasing said detentradially outwardly into engagement with said detent path.

8. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(b) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows (d) said contact path including two axially spaced,

parallel, annular insulating rows of circumferentially spaced,insulating segments spaced axially from said contact rows, respectively;

(2) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(11) a rotor within said stator and rotatable about the axis thereof;

(i) a wiping contact carried by and movable radially relative to saidrotor and slidably engaging said contact path;

(j) the axial dimension of said wiping contact being suflicient tobridge said contact rows;

(k) spring means biasing said wiping contact radially outwardly into enagement with said contact path;

(I) said spring means including two compression springs respectivelysubstantially radially aligned with said contact rows;

(in) said stator providing an annular detent path between saidinsulating roWs of said contact path; (12) said detent path havingcircumferentially spaced points of maximum radius axially aligned,respectively, with said stationary contacts of each of said contactrows;

(0) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

( 1) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(q) spring means biasing said detent radially outwardly into engagementwith said detent path.

9. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(22) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(a) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(1) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(12) a rotor within said stator and rotatable about the axis thereof;

(1) said rotor being provided therein with a longitudinally oriented,radially extending groove;

(j) a wiping contact carried in said groove and movable radially thereinrelative to said rotor and slidably engaging said contact path;

(k) the axial dimension of said wiping contact being s-ufficien-t tobridge said contact rows;

(1) spring means biasing said wiping contact radially outwardly intoengagement with said contact path;

(m) said stator providing an annular detent path between said insulatingrows of said contact path;

(It) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

() said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

( 1) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(q) spring means biasing said detent radially outwardly into engagementwith said detent path.

10. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(b) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced, parallel, annularinsulating rows of circumiferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(c) said insulating segments of one of said insulating rows beingaxially ali ned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(11) a rotor within said stator and rotatable about the axis thereof;

(1) said rotor being provided therein with a longitudinally oriented,radially extending groove;

(j) two circumferentially abutting wiping contact elements carried insaid groove and movable radially therein relative to each other and tosaid rotor and slidably engaging said contact path;

(k) the axial dimension or" said wining contact elements beingsutficient to bridge said contact rows;

(I) spring means biasing said wiping contact elements radially outwardlyinto engagement with said contact path;

(in) said stator providing an annular detent path between saidinsulating rows of said contact path;

(n) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

(0) said detent path having oircumferentially spaced points of minimumradius axially aligned, respectively with said insulating segments ofeach of said insulating rows;

(p) a etent carried by and movable radially relative to said rotor andengaging said detent path; and

(6, spring means biasing said detent radially outwardly into engagementwith said detent path.

11. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

( b) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(c) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(1) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

([1) a rotor within said stator and rotatable about the axis thereof;

(1) said rotor being provided therein with a longitudinally oriented,radially extending groove;

(j) two circumferentially abutting wiping contact elements carried insaid groove and movable radially therein relative to each other and tosaid rotor and slidably engaging said contact path;

(k) the axial dimension of said wiping contact elements being suilicientto bridge said contact rows;

(I) said wiping contact elements having convex wiping shoes slidablyengaging said contact path and extending circumferentially in oppositedirections;

(in) spring means biasing said wiping contact elements radiallyoutwardly into engagement with said contact path;

(It) said stator providing an annular detent path between saidinsulating rows of said contact path;

(0) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

(p) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

(q) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(2') spring means biasing said detent radially outwardly into engagementwith said detent path.

12. In a wiping contact rotary switch, the combination (a) an annularstator providing an annular, concave contact path;

(b) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(0) said stationary contacts of ones of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

((2') said contact path including two axially spaced, parallel, annularinsulating rows of circumferentially spaced, insulating segments spacedaxially from said contact rows, respectively;

(a) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(1) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(11) a rotor within said stator and rotatable about the axis thereof;

(i) said rotor being provided therein with a longitudinally oriented,radially extending groove;

(j) two circumferentially abutting wiping contact elements carried insaid groove and movable radially therein relative to each other and tosaid rotor and slidably engaging said contact path;

(It) the axial dimension of said wiping contact elements beingsufiicient to bridge said contact rows;

(1) said wiping contact elements having convex wiping shoes slidablyengaging said contact path and extending circumferentially in oppositedirections;

(In) spring means individually biasing said wiping contact elementsradially outwardly into engagement with said contact path;

(11) said spring means including two compression springs engaging one ofsaid wiping contact elements and respectively substantially radiallyaligned with said contact rows;

() said spring means including another compression spring engaging theother of said wiping contact elements and located between the twocompression springs first mentioned;

(p) said stator providing an annular detent path between said insulatingrows of said contact path;

(q) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said con tact rows;

(r) said detent path having circumferentially spaced points of minimumradius axially aligned, respective ly, with said insulating segments ofeach of said insulating rows;

(.9) a detent carried by and movable radially relative to said rotor andengaging said detent path; and

(t) spring means biasing said detent radially outwardly into engagementwith said detent path.

13. In a wiping contact rotary switch, the combination of:

(a) an annular stator providing an annular, concave contact path;

(17) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced,

parallel, annular insulating rows of circumferentially spaced,insulating segments spaced axially from said contact rows, respectively;

(e) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(h) a rotor within said stator and rotatable about the axis thereof;

(i) a wiping contact carried by and movable radially relative to saidrotor and slidably engaging said contact path;

(j) the axial dimension of said wiping contact being suflicient tobridge said contact rows;

(k) spring means biasing said wiping contact radially outwardly intoengagement with said contact path;

(I) the diameter of said rotor approaching the inside diameter of saidstator to provide a small, arc quenching annular clearance therebetween;

(m) said stator providing an annular detent path between said insulatingrows of said contact path;

(n) said detent path having circumferentially spaced points of maximumradius axially aligned, respectively, with said stationary contacts ofeach of said contact rows;

(0) said detent path having circumferentially spaced points of minimumradius axially aligned, respectively, with said insulating segments ofeach of said insulating rows;

( 2) a detent carried by and movable radially relative to said rotor andengaging said detent path; and (q) spring means biasing said detentradially outwardly into engagement with said detent path.

14. In a wiping contact rotary switch, the combination of (a) an annularstator providing an annular, concave contact path;

(12) said contact path including two axially spaced, parallel, annularcontact rows of circumferentially spaced, stationary contacts;

(c) said stationary contacts of one of said contact rows being axiallyaligned, respectively, with said stationary contacts of the other ofsaid contact rows;

(d) said contact path including two axially spaced,

parallel, annular insulating rows of circumferentially spaced,insulating segments spaced axially from said contact rows, respectively;

(e) said insulating segments of one of said insulating rows beingaxially aligned, respectively, with said insulating segments of theother of said insulating rows;

(f) said insulating segments of each of said insulating rows beingaxially aligned, respectively, with the circumferential spaces betweensaid stationary contacts of each of said contact rows;

(g) said insulating rows being between said contact rows;

(11) a rotor Within said stator and rotatable about the axis thereof;

(i) said rotor being provided therein with a longitudinally oriented,radially extending groove;

(1') a wiping contact carried in said groove and movable radiallytherein relative to said rotor and slidably engaging said contact path;

(k) the axial dimension of said wiping contact being sufiicient tobridge said contact rows;

(Z) said rotor being provided therein with two axially spaced, radiallyextending holes coinciding with and larger than the width of saidgroove;

(in) two compression coil springs respectively disposed in said holesand biasing said wiping contact radially outwardly into engagement withsaid contact path;

(n) said stator providing an annular detent path between said insulatingrows of said contact path; (0) said detent path having circumferentiallyspaced points of maximum radius axially aligned, respec- 15 w tively,with said stationary contacts of each of (r) spring means biasing saiddctent radially outwardsaid contact rows; 1y into engagement with saiddetent path. (p) said dctent path having circumferentially spaced pointsof minimum radius axially aligned, respsc- References Chad in the fil Ofthis Patent insulating segments of each of said UNITED STATES PATENTS(q) a detent carried by and movable radially rela- 2,473,590 Pumas etgtive to said rotor and engaging said (latent path; 2,994,743 g g- 1 and12024 334 Rhodes Mar. 6, 1962

1. IN A SWITCH, THE COMBINATION OF: (A) A STATIONARY MEMBER PROVIDING ACONTACT PATH; (B) SAID CONTACT PATH INCLUDING A CONTACT ROW OF SPACED,STATIONARY CONTACTS; (C) SAID CONTACT PATH INCLUDING AN INSULATING ROWOF SPACED, INSULATING SEGMENTS WHICH IS PARALLEL TO AND SPACED FROM SAIDCONTACT ROW; (D) SAID INSULATING SEGMENTS BEING LATERALLY ALIGNED,RESPECTIVELY, WITH THE SPACES BETWEEN SAID STATIONARY CONTACTS; (E) AMOVABLE MEMBER MOVABLE ALONG SAID CONTACT PATH; (F) A MOVABLE CONTACTCARRIED BY SAID MOVABLE MEMBER AND MOVABLE TOWARD AND AWAY FROM ANDENGAGEABLE WITH SAID CONTACT PATH; (G) SPRING MEANS BIASING SAID MOVABLECONTACT INTO ENGAGEMENT WITH SAID CONTACT PATH; (H) SAID STATIONARYMEMBER PROVIDING A DETENT PATH PARALLELING SAID CONTACT AND INSULATINGROWS OF SAID CONTACT PATH, (I) SAID DETENT PATH HAVING SPACED VALLEYSLATERALLY ALIGNED, RESPECTIVELY, WITH SAID STATIONARY CONTACTS; (J) SAIDDETENT PATH HAVING SPACED PEAKS LATERALLY ALIGNED, RESPECTIVELY, WITHSAID INSULATING SEGMENTS; (K) A DETENT CARRIED BY SAID MOVABLE MEMBERAND MOVABLE TOWARD AND AWAY FROM AND ENGAGEABLE WITH SAID DETENT PATH;AND (L) SPRING MEANS BIASING SAID DETENT INTO ENGAGEMENT WITH SAIDDETENT PATH.